87 Mj high idle/intake manifold smoke

[87ComancheHoss]

I have an 87 comanche 2.5L with 208xxx miles. I was driving it for about a minute when it started to idle at 3000 RPM. I got it home and checked to see if the throttle plate was open which it wasn't. When I opened it by hand, lots of white smoke came out of the intake manifold. Anyone know what the problem is? Thanks.

[Jeep Driver]

What happens when you try to restart it?

[87ComancheHoss]

Still idles at 3000 rpm

[Jeep Driver]

Without being there and looking at it.....................

 

 

Sounds like a massive vacuum leak. 

 

White smoke? IDK, but your intake is heated, maybe a crack?

 

I'd check the gasket at the intake to head, gasket at the TBI to intake, and check the hose going to the brake booster or the booster itself. 

[cruiser54]

Without being there and looking at it.....................

 

 

Sounds like a massive vacuum leak. 

 

White smoke? IDK, but your intake is heated, maybe a crack?

 

I'd check the gasket at the intake to head, gasket at the TBI to intake, and check the hose going to the brake booster or the booster itself. 

Yup. And the intake manifold bolts loosen up. 

[87ComancheHoss]

I was driving it around again. It was idling at 2000 for a minute and then jumped to 3000. After about 5 minutes it started idling normal again. I will go to the auto parts store and get some sensors to see if that fixes it.

[cruiser54]

I was driving it around again. It was idling at 2000 for a minute and then jumped to 3000. After about 5 minutes it started idling normal again. I will go to the auto parts store and get some sensors to see if that fixes it.

Why are you firing the parts cannon at it? 

Did you do the things we have already suggested? 

[87ComancheHoss]

Sorry it's been a while I've been busy with my other truck and jeep but I finally got time for the Comanche. I checked the intake for leaks and didn't find any. However I found a breather hose not hooked up. I hooked that up and it would still idle high. I found a bolt that you can adjust to set the idle speed, it controls how much the throttle plate is open at idle. I tightened the bolt tighter to close the throttle plate more and that has solved my problem. While I was at it I cleaned out the throttle bottle and she runs better than ever. Thanks for all the help.

[cruiser54]

Sorry it's been a while I've been busy with my other truck and jeep but I finally got time for the Comanche. I checked the intake for leaks and didn't find any. However I found a breather hose not hooked up. I hooked that up and it would still idle high. I found a bolt that you can adjust to set the idle speed, it controls how much the throttle plate is open at idle. I tightened the bolt tighter to close the throttle plate more and that has solved my problem. While I was at it I cleaned out the throttle bottle and she runs better than ever. Thanks for all the help.

Be sure to view this:

 

http://cruiser54.com/?p=94

 

And then this:

 

http://cruiser54.com/?p=54